The present invention relates generally to a tissue cassette for retaining a tissue sample having a retractable member for retracting the surface which retains the tissue sample.
After a tissue sample is collected, the tissue sample is analyzed at a lab (e.g. a pathology lab, biomedical lab, etc.) that is set up to perform the appropriate tests (such as histological analysis). In order to properly process the tissue sample a series of steps may be performed including:                1. Grossing of the sample by cutting the sample to the proper size for analysis.        2. Fixing of the sample to immobilize molecular components and/or prevent degradation.        3. Embedding the sample in an embedding material, such as paraffin wax        4. Sectioning the embedded sample by using, for example, a microtome.        
In conventional methods, the grossing step involves a lab technician cutting the tissue to the appropriate size for analysis and then placing the tissue in a tissue cassette. During the fixation stage, the cassettes are generally exposed to a fixing agent or chemical (e.g., a solution of formaldehyde in water such as formalin) shortly after sample collection. For example, U.S. Pat. No. 7,156,814 discloses a cassette which can withstand tissue preparation procedures.
After the tissue sample has been processed, the medical professional, in conventional methods, removes the tissue sample from the individual cassette to perform the embedding step. Specifically, the medical professional carefully orients the sample, based on the diagnostic view required, into a base mold containing an embedding material such as paraffin wax. Once the tissue is oriented properly in the base mold, the molten material is cooled to fully embed the tissue sample and hold it in the proper orientation. The paraffin is used to hold the sample in position while also providing a uniform consistency to further facilitate sectioning. While the term paraffin is used, this term is not limiting and describes an example of an embedding medium. Further, the term sample is not limiting and can refer to one or more tissue samples.
After the sample is embedding in paraffin, the embedded paraffin is sliced into a plurality of thin sections (e.g., 2 to 25μ thick sections), often using a microtome, for further processing and inspection. Such sectioning of the sample often helps a medical professional properly assess the sample under a microscope (e.g. diagnose relationships between cells and other constituents of the sample, or perform other assessments).
The current process requires human intervention at both the grossing and embedding steps. Such manual handling of the sample can increase the likelihood of mis-identifying the sample, cross contaminating the samples, or losing part of the sample or the entire sample. Additionally, the numerous steps of manual manipulation can often increase the time that it takes to provide a proper assessment for each sample, once the sample is collected.